/*let intervalID = setInterval(myCallback, 1000);

function myCallback() {
    console.log(Date.now());
   }*/
   let intervalID;
   function startChange() {
    if (!intervalID) {
        intervalID = setInterval(changeRandomColor, 1000);

    }
   }
   /*function changeColor() {
    if (document.body.style.backgroundColor !== "black") {
    document.body.style.backgroundColor = "black";
    document.body.style.color = "white";
    } else {
    document.body.style.backgroundColor = "white";
    document.body.style.color = "black";
    }
   }*/
    function changeRandomColor() {
        const randomColor = Math.floor(Math.random() * 16777215).
       toString(16);
        document.body.style.backgroundColor = `#${randomColor}`;
       }
   function stopChange() {
    clearInterval(intervalID);
   }
   document.getElementById("start").addEventListener("click", startChange);
   document.getElementById("stop").addEventListener("click", stopChange);
      